EXCHANGE 


31 


The  Influence  of  Sulphur  on  the  Color  of 

Azo  Dyes 

* 


DISSERTATION 


SUBMITTED  TO  THE  BOARD  OF  UNIVERSITY  STUDIES  OF 

THE  JOHNS  HOPKINS  UNIVERSITY  IN  CONFORMITY 

WITH  THE  REQUIREMENTS  FOR  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY 


BY 
WILLIAM  ROBERT  WALDRON 


BALTIMORE 
1922 


The  Influence  of  Sulphur  on  the  Cblb^'of 

Azo  Dyes 


DISSERTATION 


SUBMITTED  TO  THE  BOARD  OF  UNIVERSITY  STUDIES  OF 

THE  JOHNS  HOPKINS  UNIVERSITY  IN  CONFORMITY 

WITH  THE  REQUIREMENTS  FOR  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY 


BY 
WIUJAM  ROBERT  WALDRON 


BALTIMORE 
1922 


\ 
N/l/3 


TABLE  OF  CONTENTS 


Acknowledgment 

Outline  of  Study 

Materials 

Experimental 

Preparation  of  Intermediates 

Preparation  and  Application  of  Dyes . 

Summary -, 

Biography 


Page 
4 
5 
6 

7 
17 
23 
24 


ACKNOWLEDGMENT 

The  work  described  in  the  following  pages  was  carried  out  at  the  sug- 
gestion and  under  the  personal  supervision  of  Dr.  E.  Emmet  Reid.  The 
writer  wishes  to  thank  him  for  his  help  and  interest  in  this  work  and  for 
the  numberous  suggestions  offered.  He  also  wishes  to  thank  Drs.  Frazer, 
Patrick,  Lovelace,  Thornton  and  Morley  under  whom  he  has  received 
instruction  as  a  student  of  this  University. 

He  also  wishes  to  thank  Drs.  Stine,  Rose,  Houlehan,  Woodward,  Hitch 
and  Albright  and  Messrs.  Douglass,  Monoghan  and  Remlein  for  many 
helpful  suggestions  and  favors  obtained  through  E.  I.  du  Pont  de  Nemours 
and  Company. 


THE  INFLUENCE  OF  SULFUR  ON  THE  COLOR  OF  AZO  DYES 

The  purpose  of  the  present  investigation  was  to  study  the  effect  of  the 
sulfur  atom  and  of  the  sulfone  group,  in  various  positions,  on  the  color  of 
azo  dyes. 

Brand1  and  coworkers  found  the  — SCH3  group  to  be  strongly  batho- 
chromic  as  compared  with  — OCH3  when  introduced  into  azobenzene  or 
into  triphenyl  carbinol,  but  they  did  not  prepare  any  real  dyes  except  to 
tetrazotize  the  dimethylether  of  0,0'-dimercapto-benzidine  and  couple 
it  with  salicylic  acid,  which  gave  a  direct  yellow  on  cotton,  and  with  H- 
acid  which  gave  a  blue  shade. 

Several  workers2  have  mentioned  that  various  amines  containing  sulfur 
give  red  dyes  when  diazotized  and  coupled  with  j8-naphthol.  The  im- 
portance of  thio-indigo  and  other  dyes  containing  sulfur  appeared  to  war- 
rant a  thorough  investigation  of  the  influence  of  sulfur  in  azo  dyes. 

Two  classes  of  dyes  have  been  considered.  (1)  Those  derived  from 
mono-amines,  particularly  those  from  ^-thio-anisidine,  CH3SC6H4NH2, 
and  its  sulfone,  CHsSC^CeH^NE^,  which  have  been  contrasted  with  the 
corresponding  dyes  from  ^-toluidine  and  ^-anisidine,  thus  showing  the 
relative  effects  of  the  groups  CH3-,  CH3O-,  CH3S-  and  CH3SO2- 
as  auxochromes.  The  bases  containing  sulfur  and  the  sulfone  group 
have  been  prepared,  diazotized  and  coupled  with  a  number  of  standard 
intermediates,  such  as  R-salt  and  chromotropic  acid,  and  the  resulting 
dyes  compared  with  the  corresponding  known  dyes  containing  methyl  and 
methoxyl  groups.  In  addition  to  the  bases  containing  the  CH3S  —  group, 
a  number  have  been  made  containing  other  radicals  hi  place  of  methyl 
joined  to  sulfur,  but  the  influence  of  the  sulfur  atom  overshadows  that  of 
the  radical.  Methoxyl  is  a  much  stronger  auxochrome  than  methyl; 
the  CH3S—  group  has  been  found  to  be  stronger  still,  while  oxidation  of 
this  group  to  the  sulfone  CH3SO2—  destroys  this  effect  entirely,  the  group 
actually  appearing  as  hypsochromic.  (2)  Those  derived  from  diamines, 
which  may  be  regarded  as  benzidine  with  various  groups  interposed  be- 
tween the  two  rings.  A  number  of  bases  containing  such  groups  as  —  S— , 
-SO2— ,  —  CHjS— ,  -SCH2S-,  etc.,  between  the  two  rings  were  made 
and  dyes  prepared  by  diazotizing  and  coupling  with  standard  interme- 

1  Brand,  (a)  Ber.,  42,  3463  (1909).     Brand  and  Wirsing,  (b)  Ber.,  45,  1757  (1912); 
(c)  46,  820  (1913).     Brand  and  Stallmann,  (d)  Ber.,  54,  1578  (1921). 

2  Nietzki  and  Bothof,  (a)  Ber.,  27,  3262  (1894).     Claasz,  (b)  Ber.,  45,  1027  (1912). 


6 

diates.  The  bases  most  extensively  compared  were  benzidine,  thio-aniline, 
thio-aniline  sulfone  and  one  derived  from  mustard  gas,  NH^CeH^SCH^- 
CH2$CH2CH2SC6H4NH2.  It  was  hoped  that  the  dyes  from  these  new 
bases  would  resemble  those  from  benzidine,  but  it  appears  that  the  pe- 
culiar properties  of  benzidine  dyes  are  lost  when  the  two  rings  are  separated. 
On  the  contrary,  a  base  such  as  NI^CeKUSCHzCI^SCel^NI^  resembles 
2NH2C6H4SCH3.  The  -S-  and  -SO2-  groups  have  the  same  effects  in 
the  diamino  as  in  the  mono. 

In  all  the  dyes  made,  the  sulfur  atom  has  a  decided  bathochromic 
effect,  provided  it  is  joined  directly  to  the  ring  carrying  the  azo  chromo- 
phore  group,  but  it  has  little  effect  when  it  is  separated  from  the  ring  by 
even  a  methylene  group.  In  the  dyes  derived  from  the  two  isomeric  bases, 
NI^CeKUSCHaCeHs  and  NHaCsJ^CHaSCeHj,  the  sulfur  has  a  decided 
effect  in  the  first  case  and  practically  none  in  the  second. 

As  intermediates,  a  large  number  of  new  compounds  have  been  pre- 
pared, along  with  some  that  have  been  previously  described.  The  general 
method  has  been  to  obtain  the  nitro  compound  by  condensing  a  halide  with 
the  sodium  salt  of  ^-nitro-thiophenol,  or  ^-nitrobenzyl  bromide  with  the 
sodium  compound  of  a  mercaptan.  One  portion  of  the  product  has  been 
reduced  to  the  amino-sulfide  and  the  other  portion  oxidized  to  the  sulfone 
and  then  reduced  to  the  amino-sulfone.  The  details  of  the  numerous 
preparations  are  given  in  tables.  The  diazotizing,  coupling  and  dyeing 
were  according  to  accepted  methods 

Materials 

The  p-nitrobenzyl  bromide  used  in  this  work  was  prepared  following  the  method  of 
Brewster3  with  slight  modifications.  £-Nitro-toluene  was  brominated  in  the  sunlight 
in  Pyrex  glass  at  the  boiling  point  of  carbon  tetrachloride  which  was  used  as  solvent,  a 
trace  of  iodine  being  used  as  a  bromine  carrier.  When  the  amount  of  solvent  recom- 
mended by  Brewster  is  reduced  to  half,  the  most  of  the  />-nitrobenzyl  bromide  crystallizes 
on  cooling  to  5°,  leaving  the  oily  by-products  in  solution.  By  one^recrystallization  from 
three  parts  of  alcohol  the  compound  was  obtained  in  long  needles,  m.  p.,  99°.  By  re- 
moving the  carbon  tetrachloride  first,  the  product  was  contaminated  with  oils  which 
necessitated  two  or  three  recrystallizations  before  it  was  obtained  pure;  yield,  55-65%. 

£-Nitro-thiophenol  was  first  prepared  by  Willgerodt.4  The  preparation  has  been 
studied  and  improved  by  Mayer,5  Kehrmann  and  Bauer,6  Brand7  and  Blanksma.8 

In  the  following  work  the  sodium  salt  of  the  mercaptan  was  prepared  following  in 
part  the  methods  of  Wohlfahrt,9  Mayer,10  and  Brand.11  Brand  states  that  this  salt  is 

3  Brewster,  /.  Am.  Chem.  Soc.,  40,  406  (1918). 

4  Willgerodt,  Ber.,  18,  331  (1885). 

*  Mayer,  Ber.,  42,  3050  (1909). 

•  Kehrmann  and  Bauer,  Ber,,  29,  2362  (1896). 

7  Brand,  Ber.,  42,  3463  (1909);    45,  1757  (1912);    Ger.  pat.  228,868. 

8  Blanksma,  Rec.  trav.  chim.,  20,  138  (1901). 

«  Wohlfahrt,  J.  prakt.  Chem.,  [2]  66,  551  (1902). 
M  Mayer,  Ber.,  42,  3050  (1909). 
11  Ref.  Ic,  p.  822. 


not  stable  above  100°  and  that  its  solution  oxidizes  rapidly  in  the  air.  We  isolated  the 
salt  readily  in  a  very  pure  state,  dried  it  at  60  °,  and  found  that  it  keeps  indefinitely  with- 
out apparent  change. 

One  gram-mole  of  />-nitrochlorobenzene  is  suspended  in  150  cc.  of  alcohol,  to  which 
is  added  slowly  with  mechanical  stirring  1  mole  of  sodium  disulfide  (100%  excess)  in  600 
cc.  of  water.  The  reaction  is  exothermic  and  the  mixture  boils  by  the  time  all  of  the 
disulfide  has  been  added.  After  the  charge  has  been  stirred  for  5  minutes  it  is  poured 
into  2  liters  of  cold  water.  By  this  time  practically  all  of  the  £-nitrochlorobenzene  has 
reacted;  the  solution  contains  a  mixture  of  the  sodium  salt  of  the  mercaptan  and  the 
disulfide.  After  dilution,  the  disulfide  is  filtered  off  and  the  red  solution  acidified, 
precipitating  the  impure  free  mercaptan.  This  is  filtered  off  at  once  and  dissolved  in  500 
cc.  of  boiling  5%  sodium  hydroxide  solution.  The  hot  alkaline  solution  is  filtered  to 
remove  any  disulfide  or  impurities  carried  by  the  mercaptan.  It  is  allowed  to  cool  and 
saturated  sodium  hydroxide  solution  is  added  causing  an  almost  complete  precipitation 
of  the  sodium  salt  in  large  red  plates.  The  disulfide  residue  obtained  is  reduced  with 
sodium  hydroxide  and  sodium  sulfide,  following  the  procedure  of  Brand,  and  the  solution 
containing  the  sodium  salt  is  treated  in  the  same  way  as  described  above.  The  yields 
obtained  average  60%,  being  equally  divided  between  the  two  steps  in  the  process. 

The  £-nitrotoluene,  £-nitrochlorobenzene  and  a  large  number  of  naphthalene  inter- 
mediates used  in  this  work  were  obtained  through  the  courtesy  of  B.  I.  du  Pont  de 
Nemours  and  Company.  We  are  also  indebted  to  them  for  much  information  as  to 
carrying  out  various  processes. 

TABLE  I 
PREPARATION  AND  PROPERTIES  OP  ETHERS  OP  /WZM-NITRO-THIOPHENOL, 


Alkyl  G. 

Methyl* 17.7 

Ethyl" 8.9 

tsoPropyl 17.8 

Propyl 17.8 

isoButyl 35.5 

Butyl 17.8 

isoAmyl 17.8 

Benzyl0 17.8 

Phenacyl 6 

Hydroxyethyl 35.5 


NOaC«H4SNa  Halide    ^-Yield-^ 


G. 

G. 

% 

14.2 

12 

71 

7.8 

7 

76 

12.3 

15.5 

76 

12.3 

14 

71 

27.4 

33 

78 

13.7 

15 

71 

15.1 

15 

70 

12.6 

18 

73 

5.2 

9 

98 

16.2 

33 

82 

M. 
°  ( 


72 
44 
44.5 


123 

118 

59 


1.1963 
1.1573 
1.1625 
1.1335 


Properties 
Yellow  needles 
Yellow  needles 
Yellow  needles 
Brown  oil 
Brown  oil 
Brown  oil 
Brown  oil 
Yellow  plates 
Yellow  plates 
Yellow  needles 


a  Previously  prepared,  the  melting  points  given  in  the  literature  are:   methyl  67° 
and  71-72°,  ethyl  40°  and  benzyl  123°. 

I.     (a)  Alkyl  and  Aryl  £ara-Nitro-thiophenyl  Ethers,  RSC6H4NO2 

The  methyl,12  ethyl13  and  benzyl14  compounds  had  previously  been 
made,  the  first  two  by  the  same  method  as  used  here. 

The  alkyl  derivatives  (including  benzyl)  were  made  by  dissolving  0.1 
mole  of  the  halide  in  75  cc.  of  95%  alcohol  and  adding  0.105  mole  of  sodium 
£-nitro-thiophenate  made  into  a  thick  paste  with  water.  The  mixture 

12  Blanksma,  Rec.  trav.  chim.,  20,  400  (1901).     Ref.  10. 

13  Blanksma,  Ref.  12,  p.  403. 

14  (a)  Fromm  and  Wittmann,  Ber.,  41,  2267  (1908).     (b)  Kulenkampff,  Inaug. 
Dissertation,  Freiberg,  1906. 


8 

is  stirred  vigorously  for  5  minutes  and  then  heated  to  boiling  on  a  water- 
bath.  The  reaction  is  soon  complete,  the  solution  remaining  reddish  on 
account  of  the  slight  excess  of  sodium  mercaptide.  The  less  soluble  solid 
products  separate  as  the  solution  is  cooled  to  0°.  The  oils  were  obtained 
by  distilling  most  of  the  alcohol,  washing  the  residue  with  water  and  dil. 
alkali  and  finally  drying  with  calcium  chloride.  The  solids  are  best 
recrystallized  from  50-80%  acetic  acid. 

The  details  of  the  preparations  together  with  the  properties  of  the  prod- 
ucts are  given  in  Table  I.  Methyl  iodide,  benzyl  and  phenacyl  chlorides 
were  used  and  the  bromides  of  all  of  the  other  alkyls. 

Four  of  the  thio-ethers  are  oils  having  slight  but  peculiar  odors.  They 
could  not  be  distilled  even  at  5  mm.  pressure  on  account  of  decomposition. 
All  of  the  compounds  are  insoluble  in  water. 

Sulfur  analyses  were  made  according  to  the  method  of  Parr.15 

isoPropyl  NO2C«H4SCH(CH,)j  Calc.  16.27  Found  16.25 

Phenacyl  NO2C6H4SCH2COC8H6  11.76  11.88 

Hydroxyethyl  NOiCeH4SCH2CH2OH  16.08  16.28 

Bromo-ethyl  NO2CeH4SCH2CH2Br  12.23  12.94 

Fromm  and  Wittmann16  obtained  ^-nitrophenyl-thioglycolic  acid  by 
condensing  the  mercaptide  with  sodium  chloro-acetate.  This  and  the  cor- 
responding amine  have  also  been  prepared  by  Friedlaender  and  Chwala.17 
They  made  the  acid  from  ^-nitro-chlorobenzene  and  thioglycolic  acid  with 
sodium  hydroxide.  We  obtained  it  from  ^-nitro-thiophenol  and  chloro- 
acetic  acid  in  the  presence  of  alkali. 

The  same  reaction  took  place  with  glycol-chlorohydrin  and  sodium 
£-nitro-thiophenolate,  forming  the  thio-ether  of  monothioglycol  as  yellow 
plates;  m.  p.,  59°.  On  refluxing  this  compound  with  hydrobromic  acid 
for  several  hours  the  bromide  NC^CeEUSCH^CK^Br  was  obtained  in  86% 
yield  as  yellow  plates;  m.  p.,  58°. 

The  phenyl  derivative  was  readily  prepared  in  95%  yield  from  p-nitro- 
chlorobenzene  and  the  sodium  salt  of  thiophenol  in  alcoholic  solution. 
It  had  previously  been  made  by  Kehrmann  and  Bauer18  by  eliminating 
the  amino  group  from  £-nitro-£'-amino-diphenyl  sulfide. 

Esters  of  ^-Nitro-thiophenol 

Esters  were  readily  obtained  by  using  benzoyl  chloride,  phosgene  and 
thiophosgene.  These  were  recrystallized  from  about  50%  acetic  acid  as 
they  are  too  soluble  in  strong  acetic  acid.  Sulfones  could  not  be  obtained 
by  oxidizing  these  esters.  On  reduction,  only  the  ^-nitrophenylthiol- 

16  Parr,  J.  Ind.  Eng.  Chem.,  11,  230  (1919). 

16  Ref.  14a,  p.  2273. 

17  Friedlaender  and  Chwala,  Monalsh.,  28,  274  (1907). 

18  Kehrmann  and  Bauer,  Ber.,  29,  2364  (1896). 


benzoate  (6  g.)  gave  the  desired  amine  (4  g.;  75%);  m.  p.,  115°.    The 
calculated  percentage  of  sulfur  was  14.01;    that  found,  14.10. 

PREPARATION  AND  PROPERTIES  OF  ESTERS  OP  £ara-NiTRo-TmopHENOL 

Sulfur      ' 

NO2C6H4SNa  ,—  Yield—  >     M.  p.       Calc.        Found 
Formula  G.         G.       %         °  C.  %  %  Properties 

NO2C8H4SCOC6H5.  ...     17.7     14     54     123  .  7     12  .  39     12  .  42    Yellow  plates 

(NO2C«H4S)CO  ......     18        11     64     174.5     19.04     19.46    Yellow  powder 

(NO2C6H4S)CS  .......     18        10     55     141        27.28    27.10     Buff  powder 

The  chlorides  of  £-toluene-sulfonic  and  w-nitrobenzene  sulfonic  acids 
were  used  in  the  same  way  but  the  desired  esters  could  not  be  obtained. 
(b)  Alkyl  and  Aryl  ^am-Amino-thiophenyl  Ethers,  RSC6H4NH2 

The  methyl19  compound  had  been  prepared  by  the  reaction  of  £-aceto- 
amino-thiophenol  on  methyl  sulfate  with  the  subsequent  removal  of  the 
acetyl  group,  and  the  ethyl,2()  phenyl21  and  benzyl145  compounds  by  the 
reduction  of  the  corresponding  nitro  compounds  with  tin  and  hydrochloric 
or  acetic  acid.  We  considered  that  reductions  with  iron  and  a  trace  of 
acetic  acid,  though  much  slower,  would  obviate  the  danger  of  splitting  the 
molecule  at  the  sulfur  atom.  The  method  with  iron  was  found  to  be  quite 
satisfactory. 

To  5  g.  of  the  nitro  compound  is  added  15  g.  of  iron  dust,  0.1  cc.  of  coned,  acetic  acid 
and  100  cc.  of  water,  and  the  charge  is  stirred  for  10  hours  at  85-90°.  At  the  end  of 
this  time  the  mixture  is  made  alkaline  with  sodium  carbonate  and  filtered.  The  filtrate 
is  shaken  with  benzene  to  obtain  the  oil  and  the  iron  residue  extracted  four  times  with 
hot  benzene.  The  combined  extract  is  distilled  on  a  water-bath,  the  last  traces  of  ben- 
zene being  removed  by  applying  a  vacuum.  The  oil  is  then  added  to  100  cc.  of  5%  sul- 
furic  acid  and  the  difficultly  soluble  sulfate  so  obtained  is  recrystallized  from  boiling 
water,  a  small  amount  of  diatomaceous  earth  being  added  to  remove  any  tar.  The  yields 
in  all  cases  are  85-90%. 

TABLE  II 

PREPARATION  AND  PROPERTIES  OF  £ara-AMiNOPHENYL  ALKYL  OR  ARYL  SULFIDES, 

NH2C6H4SR 

Nitro  Sulfur 


Alkyl  or                        compound  ^-Yield-^  M.  p.            .25  Calc.        Found 

aryl  G.  G.  %  °  C.           d25  %                  % 

Methyl0  ...........  10  8  97  ..         1.1425 

Ethyl"  ............  5  4  95  ..          1.1010 

tsoPropyl  ..........  10  7  82  ......  7  .41        7  .45 

Propyl  ............  10  7.5  88  ......  7.41         7.30 

isoButyl  ...........  10  8  93  .  .         1  .0421  6  .96        7  .08 

Butyl  .............  10  8  93  ......  6.96        7.08 

isoAmyl  ...........  10  8  92  ......  6.57        6.62 

Phenyl"  ...........  18.5  10  62  95.8         ____ 

Benzyl0  ...........  12  8.5  81  ..         1.1321 

Phenacyl  ..........  9  7  87  111.5         ____  13.19       13.59 

0  Prepared  by  other  authors;  the  phenyl  is  given  as  melting  at  93°  and  95°. 


19  Zincke  and  Jorg,  Ber.,  42,  3368  (1909);   b.  p.,  140°  (15  mm.). 

20  Monier- Williams,  Soc.,  89,  278  (1906);    b.  p.,  280-281°. 

21  Ref.  18;  m.  p.,  93°;    acetyl,  146°. 


10 


All  of  these  bases  except  the  phenyl  are  oils  with  practically  no  odors; 
they  darken  rapidly  in  the  light  and  the  solubility  of  the  sulf  ates  decreases 
rapidly  with  increase  in  molecular  weight,  the  sulf  ate  of  the  benzyl  com- 
pound being  almost  insoluble  in  boiling  water.  The  hydrochlorides  are 
much  more  soluble  and  may  be  obtained  by  saturating  the  benzene  solu- 
tion of  the  base  with  dry  hydrogen  chloride. 

Details  of  the  preparations  and  the  properties  of  the  compounds  are 
given  in  Table  II.  The  sulf  ates  of  the  bases  were  analyzed  by  dissolving 
in  hot  water  and  adding  barium  chloride  solution,  the  figures  given  being 
the  sulfur  in  the  sulfate  ion. 


(c)  Alkyl    and    Aryl    ^ara-Nitrophenyl    Sulfones, 

Three  sulf  ones  of  this  series  have  been  prepared  previously;  the  me- 
thyll4b  and  benzyl22  by  the  oxidation  of  the  corresponding  sulfides  with 
chromic  acid  and  the  phenyl28  by  the  reaction  of  £-nitro-chlorobenzene 
on  benzene  sulfmic  acid  under  pressure.  The  chromic  acid  method  was 
used  in  this  work. 

Ten  g.  of  the  sulfide  is  dissolved  in  100  cc.  of  80%  acetic  acid  and  the  mixture  heated 
to  boiling,  then  a  saturated  solution  of  chromic  acid  in  water  is  added  a  little  at  a  time 
until  an  orange  coloration  denotes  the  presence  of  an  excess.  After  boiling  for  15  min- 
utes, an  equal  volume  of  water  is  added  and  the  solution  allowed  to  cool.  The  sulfone 
separates  and  is  recrystallized  from  50%  acetic  acid  to  remove  chromium  compounds. 
The  sulfones  are  obtained  as  white  plates  or  needles  which  are  recrystallized  to  constant 
melting  point. 

The  sulfones  are  white  solids,  crystallizing  very  well  from  acetic  acid  or 
alcohol.  They  are  very  stable  towards  oxidizing  agents,  as  none  of  them 
shows  any  tendency  to  break  at  the  sulfur  atom  forming  sulfonic  acids. 

TABUS  III 

PREPARATION  AND  PROPERTIES  OP  />ara-NiTROPHENYL  ALKYL  OR  ARYL  SULFONES, 

N02C6H4S02R 


Alkyl  or 
aryl 


Nitro 
sulfide 


Sulfur 


Yield 
G. 

% 

M.  p. 
0  C. 

Calc. 
% 

Found 
% 

Form 

10 

84 

142.5 

15.97 

16.02 

Needles 

9 

76 

138.5 

14.91 

14.98 

Plates 

8 

86 

115.3 

14.01 

14.41 

Plates 

10 

86 

114 

14.01 

14.32 

Plates 

10 

87 

73 

13.20 

13.25 

Needles 

12 

70 

56.4 

13.20 

13.28 

Plates 

12 

70 

62.5 

12.49 

12.55 

Plates 

22.5 

88 

142 

.  . 

.  .  . 

Plates 

5.5 

97 

172 

.  . 

. 

Plates 

Methyl0 10 

Ethyl 10 

w0Propyl 8 

Propyl 10 

isoButyl 10 

Butyl 15 

isoAmyl 15 

Phenyl" 22 

Benzyl0 5 

*  Prepared  by  other  authors  who  give  the  melting  point  of  the  methyl  as  136  °,  the 
phenyl  143°,  and  the  benzyl  169°. 

22Ref.  14a,  p.  2270.     Ref.   14b. 

«  Ullmann  and  Posdermadjian,  Ber.,  34,  1154  (1901). 


11 


The  oxidation  with  chromic  acid  is  exothermic;  at  the  same  time  the 
product  is  purified  by  oxidation  of  any  disulfides  present  to  soluble  sul- 
fonic  acids.  The  sulfones  with  low  melting  points  separate  from  the  ox- 
idizing mixture  as  oils  but  solidify  after  standing  for  several  hours.  The 
yields  are  about  85%. 

Details  of  the  preparations  are  given  in  Table  III  together  with  proper- 
ties of  the  products.  The  analyses  were  made  by  the  method  of  Parr. 

(d)  Alkyl   and   Aryl   £ara-Ammophenyl   Sulfones,   RSC^CeH^I^ 

Two  of  this  series  of  amino  sulfones  have  been  prepared  previously, 
the  methyll4b  and  phenyl24  derivatives  by  the  reduction  of  the  nitro 
bodies  with  tin  and  hydrochloric  acid. 

We  have  prepared,  others  by  reduction  from  the  corresponding  nitro 
compounds  described  above. 

Five  g.  of  the  nitrophenyl  sulfone  is  reduced,  following  the  same  procedure  as  used 
in  the  case  of  the  nitrophenyl  sulfides.  When  the  reduction  is  finished  the  charge  is 
diluted  with  two  volumes  of  water,  heated  to  boiling  and  filtered  hot.  In  the  case  of  the 
first  7  products,  the  iron  residue  is  extracted  twice  more  with  500  cc.  of  hot  water,  but 
with  the  last  two  alcohol  is  used,  since  they  are  not  very  soluble  in  water.  The  water  or 
alcohol  extracts  are  cooled  to  0°,  at  which  a  large  percentage  of  the  product  crystallizes; 
but  in  the  case  of  the  methyl  and  ethyl  derivatives  it  is  necessary  to  evaporate  to  a  small 
volume  before  any  solid  is  obtained.  The  yields  are  about  90%,  being  low  in  the  case  of 
the  methyl  and  ethyl  compounds  on  account  of  their  greater  solubility. 

The  amino  sulfones  are  white,  odorless  solids,  and  are  much  more  sol- 
uble than  the  corresponding  amino  sulfides,  the  solubility  decreasing  with 
increase  in  the  size  of  the  radical.  The  first  4  numbers  of  the  series  melt 
lower  than  the  corresponding  nitro  compounds  while  the  last  5  melt  higher. 
The  methyl  and  ethyl  compounds  darken  considerably  on  standing  in 
light  and  air  but  the  others  remain  white. 

Details  of  the  preparations  are  given  in  Table  IV. 

TABLE  IV 

PREPARATION  AND  PROPERTIES  OP  £am-AMiNOPHENYL  ALKYL  OR  ARYL  SULFONES, 

RSO2C6H4NH2 


Alkyl  or 
aryl 

Methyl0  

Nitro 
sulfone 
G. 

10 

^—  Yield—  > 
G.          % 

6        70 

4      46 
7      80 
12      92 
8      91 
8      91 
9      92 
8      90 
4      89 

M.  p. 

0  c. 
133 
89.3 
122 
97 
83.7 
109 
110 
176 
218.5 

Sulfur 
Calc.          Found 
%                  % 

18.74       19.13 
17.33       17.29 
16.10       16.29 
16.10       16.37 
15.06       15.52 
15.06       15.28 
14.12       13.97 

Form 
Plates 
Plates 
Needles 
Needles 
Plates 
Needles 
Needles 

Ethvl 

10 

isoPropyl  

....     10 

ProDvl 

.     15 

isoButyl 

10 

Butyl  

...     10 

isoAmyl  .   .  . 

11 

Phenyl0 

10 

Benzyl.  . 

5 

12.99 

13.11 

Needles 

0  Prepared  by  other  authors  who  give  the  melting  point  of  the  methyl  as  137°,  and 
the  phenyl  176°. 

24  Ref.  23,  p.  1155. 


12 

II.     (a)  Alkyl    and    Aryl    £ara-Nitrobenzyl    Sulfides, 

No  para  derivatives  of  this  class  have  been  made  though  ortho*'0  and 
meta™  nitrobenzyl-methyl  sulfides  have  been  prepared  and  also  the  corre- 
sponding amines.  In  these  cases  the  sodium  salt  of  the  nitrobenzyl  mer- 
captan  was  used  with  methyl  iodide.  As  the  para  mercaptan27  is  rather 
difficult  to  prepare,  it  was  thought  that  the  para  sulfide  could  be  obtained 
by  the  reaction  of  £-nitrobenzyl  bromide  on  the  sodium  salt  of  the  various 
mercaptans. 

The  methyl  and  ethyl  derivatives  could  not  be  prepared  in  this  way  as, 
on  adding  a  solution  of  the  theoretical  quantity  of  sodium  ethylate  satu- 
rated with  an  excess  of  the  mercaptans  to  ^-nitrobenzyl  bromide,  p,p'- 
dinitro-dibenzyl  sulfide,28  m.  p.,  159°,  resulted,  though  the  butyl,  isoamyl 
and  phenyl  derivatives  were  thus  obtained,  using  the  mercaptans. 

One- tenth  g.-mole  of  £-nitrobenzyl  bromide  is  dissolved  in  100  cc.  of  alcohol  and 
heated  to  60°.  To  this  is  added  0.1  mole  of  sodium  mercaptide  made  by  adding  an  al- 
cohol solution  of  0.1  mole  of  sodium  ethylate  to  the  mercaptan.  This  is  added  slowly 
with  rapid  agitation  at  60°  and  after  15  minutes  the  alcohol  is  distilled  and  the  excess 
of  mercaptan  distilled  with  steam.  The  oil  is  washed  with  water  and  dried  with  calcium 
chloride.  In  the  case  of  the  phenyl  compound  which  is  solid  it  is  recrystallized  from 
alcohol.  Details  are  given  in  Table  V. 

The  mercaptan  salt  has  no  apparent  reducing  action  on  the  nitro  group 
when  p-nitrobenzyl  bromide  is  still  present  in  excess,  but  beyond  this  point 
it  reduces  the  sulfide  to  a  red  substance  which  is  probably  an  azo  com- 
pound. Excess  of  the  free  mercaptan  has  no  effect,  the  sodium  salt  being 
necessary  for  the  reduction.  The  reaction  seems  best  at  60-70°,  for  at 
room  temperature  the  p-nitrobenzyl  bromide  is  rather  insoluble  in  alcohol. 
The  phenyl  compound  is  solid  and  may  be  purified  by  crystallization 
from  alcohol  or  acetic  acid.  The  butyl  and  isoamyl  derivatives  are 

TABUS  V 

PREPARATION  AND  PROPERTIES  OF  £ara-NiTROBENZYi,  Aucvn,  OR  ARYI,  SULFIDES, 

N02C6H4CH2SR 


Alkyl 
or 

RSH 

Na 

,  Yield  s 

M.  p. 

,25 

Sulfur 
Calc.        Found 

aryl 

G. 

G. 

G. 

G. 

% 

°C. 

d25 

t 

?o 

%       Form 

Butyl... 

77.7 

43.2 

8.28 

62 

76.6 

1 

.1462 

14 

.25 

...       Oil 

isoAmyl 

32.4 

16.2 

3.45 

33.7 

94 

1 

.1513 

13 

.41 

...        Oil 

Phenyl.. 

17.2 

8.8 

1.84 

14.5 

74.3 

79 

.  .  .  . 

13 

.10 

13.26     White  plates 

higher-boiling  oils  which  decompose  on  distillation  at  5  mm.  pressures. 
They  have  an  odor  similar  to  the  corresponding  oils  in  the  previous  series. 
The  yields  are  about  75%. 

25  Gabriel  and  Stelzner,  Ber.,  29,  163  (1896). 
28  Lutter,  Ber.,  30,  1070  (1897);   m.  p.,  31°. 

27  Waters,  Inaug.  Dissertation,  Munich  (1905). 

28  Otto  Fischer,  Ber.,  28,  1337  (1895). 


13 

(b)  Alkyl  and  Aryl  ^-Aminobenzyl  Sulfides, 
These  compounds  are  prepared  in  the  same  way  as  the  amino  sulfides 
of  the  previous  series,  and  resemble  them  in  properties,  the  phenyl  com- 
pound being  solid  also,  but  having  a  lower  melting  point.  The  oils  were 
isolated  as  the  slightly  soluble  sulfates  which  were  recrystallized  to  remove 
p-aminobenzoic  acid. 

TABLE  VI 

PREPARATION  AND  PROPERTIES  OP  />ara-AMiNOBENZYL  ALKYL  OR  ARYL  SULFIDES, 

NH2C6H4CH2SR 

Alkyl  Nitro  Sulfur0 

or  sulfide  ,— Yield-^     M.  p.          .25  Calc.  Found 

aryl  G.  G.         %          °  C.        d25  %  % 

Butyl 13"         10      89       ..       1.0321         6.66        6.75 

isoAmyl 10  8      41  1.0307        6.20        6.28 

Phenyl 7.25        6      94      72         ....         14.91       35.13 

a  The  first  two  of  the  series  are  oils,  and  the  analyses  were  therefore  made  on  the 
sulfates  of  the  bases,  only  the  sulfur  in  the  sulfate  ion  being  determined.  These  sul- 
fates are  obtained  as  curdy  precipitates,  very  slightly  soluble  in  cold  water,  something 
like  1  g.  per  liter.  On  recrystallization  from  hot  water,  they  separate  in  flocculent  form. 

(c)  Alkyl  and  Aryl  ^ara-Nitrobenzyl  Sulfones 

The  sulfones  of  this  class  are  prepared  in  the  same  way  as  those  of  the 
previous  series.  They  are  crystalline  solids,  and  are  formed  with  a  good 
yield, — about  75%.  The  butyl  and  ^oamyl  compounds  are  contaminated 
with  5-10%  of  £-nitrobenzoic  acid,  which  lowers  their  melting  points  and 
which  it  is  practically  impossible  to  eliminate  by  crystallization.  It  is 
removed  by  agitating  several  times  with  a  large  volume  of  5%  solution  of 
sodium  carbonate.  The  sulfones  may  be  recrystallized  from  acetic  acid 
or  alcohol.  They  are  very  slightly  soluble  in  water;  when  the  oxidation 
is  carried  out  with  a  water  suspension  of  the  sulfide  a  poor  yield  of  sulfone 
contaminated  with  tar  is  obtained.  Hot  20%  sodium  hydroxide  solution 
decomposes  the  sulfones,  giving  a  red  solution  and  a  yellow  precipitate 
(m.  p.,  195°)  which  contains  no  sulfur  and  is  probably  a  compound  of  the 
formula  NOaCe^CHiCHCeJ^NC^  (m.  p.,  210-216°). 

A  similar  decomposition29  has  been  noted  with  sulfone  esters. 

TABLE  VII 

PREPARATION  AND  PROPERTIES  OF  £ara-NiTROBENZYL  ALKYL  OR  ARYL  SULFONES, 

N02C6H4CH2S02R 

Nitro  Sulfur 

Alkyl  or  sulfide        , — Yield <         M.  p.  Calc.          Found 

aryl  G.  G.  %         °  C.  %  %  Form 

Butyl 33  19          50       139.5       12.49       12.40      Plates 

w<?Amyl 36.5      31  75       117  11.83       11.81       Plates 

Phenyl 7.2        7.2      88      209.5       11.58      11.51       Plates 

(d)  Alkyl  and  Aryl  £ara-Aminobenzyl  Sulfones,  NEkCd^CHaSC^R 

The  amino  sulfones  are  prepared  in  the  same  way  as  those  of  the  former 
series,  starting  with  material  free  from  £-riitrobenzoic  acid,  and  have 
«  Michael  and  Comey,  Am.  Chem.  /.,  5,  349  (1883-84). 


Nitro 
sulfone 
G. 

^-Yi 
G. 

6  % 

M.  p. 
0  C. 

Sulfur 
Calc.        Found 

Form 

8 

6 

85 

95 

14.11 

13.9 

Needles 

11 

7 

71 

126 

13.30 

13.32 

Needles 

7.2 

4 

62 

180 

13.00 

13.20 

Needles 

14 

similar  properties.  They  are  removed  from  the  iron  residue  by  extraction 
with  alcohol.  They  were  recrystallized  by  dissolving  in  hot  alcohol, 
adding  water  cautiously  to  incipient  separation  and  cooling. 

TABUS  VIII 

PREPARATION  AND  PROPERTIES  OF  ALKYI,  OR  ARYL  ^am-AMiNOBENZYL  SULFONES, 

NH2C6H4CH2S02R 

N: 

Alkyl  or 
aryl 

Butyl 

isoAmyl 11 

Phenyl 7.2 

III.     (a)  £,£'-Dinitro-diphenyl  Derivatives  with  Various  Groups  between 
the  Two  Rings,  NO2C6H4.X.C6H4NH2 

In  this  series  of  compounds,  £,£'-dinitro-diphenyl  may  be  considered 
the  simplest  member,  the  more  complicated  ones  consisting  of  various 
radicals  containing  sulfur  between  the  two  rings,  X  in  the  above  formula 
standing  for  the  following  groups:  -S-,  -CH2S-,  -CH2SCH2-, 
-SCH2S-,  -SC2H4S-,  -SC3H6S-,  -SC2H4SC2H4S-,  -SC2H4SO2- 
C2H4S-. 

Nietzki  and  Bothof2a  prepared  dinitro-diphenyl  sulfide  by  treating  p- 
nitro-chlorobenzene  with  sodium  sulfide.  This  reaction  was  rather  slow 
and  did  not  go  to  completion.  £,£'-Dinitro-benzylphenyl  sulfide  was 
formed  from  ^-nitrobenzyl  bromide  and  sodium  £-nitro-thiophenol.  p,p'- 
Dinitro-dibenzyl  sulfide  was  prepared  by  Fischer28  from  ^-nitrobenzyl 
chloride  and  ammonium  sulfide.  Others  of  the  series  containing  two  or 
more  separated  sulfur  atoms  we  obtained  from  two  molecules  of  sodium 
£-nitro-thiophenolate  with  the  following  halides,  methylene  iodide,  ethyl- 
ene  bromide,  trimethylene  bromide,  benzal  chloride,  mustard  gas  and 
mustard  gas  sulfone.  In  all  cases  the  reaction  took  place  at  once  with 
the  separation  of  the  new  compound.  Methylene  chloride  did  not  react 
at  all  because  of  its  low  boiling  point  and  the  inactivity  of  the  chlorine 
atoms;  hence,  the  iodide  was  used.  In  the  case  of  ethylene  bromide  the 
reaction  took  place  on  warming  to  70°,  but  when  one  ethylene  hydrogen 
has  been  replaced  by  methyl,  as  in  propylene  dibromide,  the  reaction  is 
much  slower  and  the  resulting  compound  was  contaminated  with  a  large 
amount  of  disulfide,  produced  by  oxidation  of  the  mrecaptan  either  by 
the  nitro  group  or  by  air.  This  takes  place  only  to  a  very  limited  extent 
when  the  reaction  is  rapid.  This  was  borne  out  by  the  fact  that  using 
butylene  dibromide,  in  which  two  ethylene  hydrogen  atoms  have  been 
replaced  by  methyl,  the  desired  reaction  was  so  slow  that  the  product  ob- 
tained consisted  almost  entirely  of  disulfide. 

Mustard  gas  and  its  sulfone  both  react  immediately  with  the  mercaptide, 
their  chlorine  atoms  being  much  more  active. 


15 


These  nitro  sulfides  are  yellowish,  odorless  solids  which  crystallize 
well  from  acetic  acid,  and  are  insoluble  in  water  and  only  slightly  soluble 
in  alcohol.  The  yields  average  about  85%. 

Inasmuch  as  the  different  compounds  are  made,  using  several  inter- 
mediates, and  the  preparation  is  self-explanatory  from  Table  IX,  fol- 
lowing, it  will  suffice  to  describe  one  completely,  the  others  being  made 
in  the  same  way. 

One-  tenth  g.-mole  of  methylene  iodide  is  dissolved  in  100  cc.  of  alcohol  and  0.21 
mole  of  sodium  £-nitro-thiophenolate,  with  enough  water  to  produce  a  thick  paste,  is 
added.  The  mixture  is  stirred  while  being  heated  on  a  water-bath  to  65-70°.  After  a 
few  minutes  at  this  temperature,  the  reaction  is  complete  and  the  solid  sulfide  partly 
precipitates.  On  cooling  to  0  °,  practically  all  of  the  sulfide  separates  and  is  filtered  off. 
It  is  purified  by  boiling  with  a  1%  sodium  carbonate  solution  and  recrystallized  from 
80%  acetic  acid  in  which  it  is  fairly  soluble  hot,  and  very  slightly  so  cold;  the  latter 
treatment  removes  any  dinitro-diphenyl  disulfide  formed. 

TABLE  IX 

PREPARATION  AND  PROPERTIES  OF  £,/>'-DINITRO-DIPHENYI<  COMPOUNDS,  NO2C6H4  —  X  — 

C6H4N02 


Mercaptide  Halide 
X                                      G.            G. 

s  —  Yicl 
G. 

d-^ 

M.  p. 
°C. 

Sulfur 
Calc.        Found 

Properties 

—  s—  • 

7 

.8 

31.5 

10 

36 

154 

.  , 

,  . 

Orange  plates 

—  CH2S— 

17 

.8 

21.6 

27.4 

94 

108 

11 

.07 

10 

.99 

Pale  yellow  plates 

=  (CH2)2Sa 

9 

.6 

17.28 

11.5 

95 

159 

.  , 

Yellow  needles 

—  SCHjS— 

35 

.4 

26.7 

23.5 

83 

179 

19 

.88 

19 

.83 

Olive  plates 

-S(CH2)2S- 

17 

.7 

9.4 

10 

60 

136 

19 

.06 

19 

.11 

Yellow  plates 

-S(CH2)3S— 

35 

.4 

20.2 

32 

91 

110 

18 

.29 

18 

.33 

Yellow  plates 

—  SCH(C6H6)S— 

35 

.4 

16.1 

30 

75 

150.5 

16 

.09 

16 

.03 

Yellow  needles 

=  (SCH2CH2)2S 

17 

.7 

8 

15 

76 

86.5 

24 

,28 

24 

.29 

Yellow  plates 

=  (SCH2CH2)2S02 

27 

.7 

14.5 

25 

77 

170 

22 

.48 

22 

.48 

Pale  yellow  plates 

0  Previously  known,  the  melting  points  being  given  as  154°  and  159°,  respectively. 

(b)  £,£'-Diamino-diphenyl  Compounds  (NK^CeHs^X 
Two  amines  of  this  group  have  been  made  previously.  Nietzki  and 
Bothof2a  prepared  thio-aniline  by  reducing  the  dinitro  derivative,  while 
Mertz  and  Weyth30  prepared  it  by  a  fusion  of  aniline  with  sulfur.  O. 
Fischer31  reduced  dinitro-dibenzyl  sulfide  to  the  corresponding  diamine 
with  tin  and  hydrochloric  acid.  We  have  prepared  these  and  the  other 
amines  of  this  group  by  reducing  the  dinitro  compounds  just  described 
with  iron  and  acetic  acid  as  outlined  above.  Benzene  was  used  for  ex- 
tracting the  amines  from  the  iron  residue.  On  concentrating  and  cooling 
the  benzene  solutions,  the  amines  were  usually  obtained  as  crystals.  One 
of  them  is  an  oil. 

The  amines  are  very  slightly  soluble  in  water,  more  soluble  in  alcohol 
and  very  soluble  in  benzene.  The  solubility  in  all  cases  decreases  rapidly 
with  increase  in  molecular  weight. 

30  Mertz  and  Weyth,  Ber.,  3,  978  (1870). 

31  Ref.  28,  p.  1338. 


16 


PREPARATION  AND  PROPERTIES  OF  p,p'-  DIAMINO-DIPHENYL  COMPOUNDS,  NH2C6H4—  X— 


Nitro  comp.        x— 


M.  p. 


Sulfur 


Calc. 


Found 


X 

G. 

G. 

% 

0  c. 

% 

% 

Properties 

—  S—  " 

108 

Needles 

—  CH2S— 

10 

6 

76 

93 

13 

.92 

14 

.10 

Flat  needles 

=  (CH2)2Sa 

5.5 

3 

68 

105 

White  plates 

—  SCH2S— 

10 

7 

.5 

92 

99 

24 

.43 

24 

.47 

Red  needles 

—  S(CH2)2S— 

10 

7 

.25 

88 

111 

23 

.20 

23 

.28 

Red  needles 

—  S(CH2)3S— 

5.5 

4 

87 

8 

.26* 

7.97 

Oil 

—  SCH(C6H6)S— 

10 

7 

.5 

88 

131 

18 

.93 

18 

.40 

White  needles 

=  (SCH2CH2)S 

6 

4 

.5 

88 

93 

28 

.60 

28 

.54 

Red  needles 

=  (SCH2CH2)S02 

6 

5 

97 

149 

26 

.12 

26 

.22 

White  needles 

0  Previously  prepared,  the  melting  points  being  given  as  108°  and  105°,  respectively. 
6  In  the  sulfate  ion  of  the  sulfate. 

(c)  Sulfones  from  the  Dinitro-diphenyl  Compounds 
Fromm  and  Wittmann32  prepared  dinitro-diphenyl  sulfone  by  oxidizing 
the  sulfide  dissolved  in  acetic  acid  with  chromic  acid.  Following  the 
procedure  described  above  for  preparing  mononitro  sulfones,  we  obtained 
disulfones  in  all  cases  except  from  £,£'-dinitro-diphenyl-dithiomethane, 
where  the  two  sulfur  atoms  are  separated  only  by  a  CH2  group  and  oxida- 
tion breaks  the  molecule,  yielding  only  soluble  sulfonic  acids.  Various 
oxidizing  agents  were  tried  with  the  same  result.  In  the  case  where  the 
two  sulfur  atoms  were  separated  by  two  CH2  groups,  no  difficulty  was 
encountered  even  when  three  sulfur  atoms  are  present. 

The  sulfones  are  insoluble  in  water,  slightly  soluble  in  alcohol,  and 
fairly  soluble  in  boiling  80%  acetic  acid,  the  last  member,  however,  being 
insoluble  in  this,  as  the  solubility  of  the  series  decreases  markedly  with 
the  increase  in  molecular  weight.  They  are  white  solids  with  high  melting 
points,  and  are  obtained  in  yields  averaging  75%. 

TABUS  XI 

PREPARATION  AND  PROPERTIES  OP  SULFONES  FROM  p,p '-DINITRO-DIPHENYL 
COMPOUNDS,  NO2C6H4.X.C6H4NO2 

Nitrosulfide  ^Yield—     M.  p.  Calc.  "  Found 

— SO2— 

— CH2S02— 

=  (CH2)2S02 

— SO2(CH2)2SO2— 

— S02(CH2)3S02— 

=  (S02CH2CH2)2S02 

(d)  Reduction  Products  of  £,£ '-Dinitro-diphenyl  Sulfones 
The  preparation  of  diamino  sulfones  is  much  more  difficult  than  that 
"Ref.  14a,  p.  2270;    m.  p.,  282°. 


G. 

G. 

% 

0  c. 

% 

% 

\ 

Form 

12 

11 

82 

282 

Needles 

13 

.7 

13.7 

90 

195 

9. 

95 

10 

.03 

Plates 

6 

5 

75 

260 

9. 

54 

9 

.49 

Needles 

10 

9 

75 

235 

dec 

16. 

02 

16 

,16 

Needles 

12 

.5 

7 

47 

208 

15. 

48 

15 

59 

Needles 

12 

11 

80 

235  dec 

19. 

54 

19. 

68 

Needles 

17 

of  the  mono-amine  sulfones  in  Classes  I  and  II.  Fromm  and  Wittmann33 
obtained  diamino-diphenyl  sulfone  by  reducing  the  corresponding  nitro- 
sulfone  with  tin  and  acid.  This  reduction  also  took  place  with  iron  and 
acetic  acid  but  on  carrying  it  to  the  next  member  of  the  saries,  p,p'-dmitro- 
benzylphenyl-sulfone,  a  compound  was  obtained  which  seemed  by  analysis 
to  be  a  nitro-amino  sulfone  and  could  not  be  reduced  further  by  this 
means;  m.  p.,  215°  (decomp.).  Analysis:  Calc.  for  S,  10.98.  Found: 
1  1  .26.  Dinitro-dibenzyl  sulfone  yielded  a  white,  tarry  substance. 

These  last  two  reductions  were  readily  effected  by  using  tin  and  hydro- 
chloric acid  in  alcohol,  the  tin  double  salt  separating  on  cooling.  From 
this  the  desired  base  was  obtained. 

In  the  case  of  the  di-  and  tri-sulfones,  neither  method  of  reduction  was 
satisfactory.  According  to  the  analyses  of  the  compounds  isolated,  both 
nitro  groups  had  been  reduced,  and  also  one  sulfone  group  to  a  sulfide; 
or  both  sulfone  groups  to  sulfoxide,  this  being  the  case  with  the  di-  and 
tri-sulfones.  Various  methods  of  reduction  were  tried  but  the  desired 
compounds  were  not  obtained;  according  to  the  analyses, 


TABUS  XII 

PREPARATION  AND  PROPERTIES  OF  £,£'-DIAMINO-DIPHENYI,  SUI<FONES,  NH2C6H4.X.C6- 

H4NH2 

Nitro 

^—          —  > 
X 

—  SO2—  • 

—  CH2S02— 
=  (CH2)2SO2 

0  Previously  prepared. 


Nitro 
compound  ^—  Yield—  « 
G.         G.         % 

M.  p. 
°C. 

Sulfur 
Calc.        Found 
%               % 

Properties 

4 

2.5 

78 

176.5 

Yellow  needles 

10 

7 

86 

216 

12.22 

12.28 

White  plates 

5 

3 

73 

187.5 

11.60 

11.91 

Yellow  needles 

reduced  to  the  compound 
calc.  :    S,  20.75;  found,  20.87;  m.  p.,  206°  (chars). 

Preparation  and  Application  of  the  Dyes 
1.  From  Mono-amines.    See  Tables  II,  IV,  VI  and  VIII 

One-hundredth  g.-mole  of  the  base  (in  case  it  is  liquid  the  equivalent  quantity  of 
the  sulfate)  is  dissolved  in  two  equivalents  of  hydrochloric  acid  in  75  cc.  of  water,  and 
diazotized  with  one  equivalent  of  sodium  nitrite  at  5°,  maintaining  an  excess  of  nitrate  for 
a  half-hour,  as  shown  by  the  starch-potassium  iodide  test.  One-hundredth  mole  of  R- 
salt,  plus  5%  excess,  is  dissolved  in  50  cc.  of  water  to  which  have  been  added  two  equiva- 
lents of  sodium  carbonate,  and  the  mixture  is  cooled  to  5°.  The  diazo  solution  is  added 
to  the  alkaline  solution  of  R-salt  at  this  temperature,  and  the  whole  stirred  half  an  hour. 
In  some  cases  the  dye  separates  immediately,  while  in  others  it  remains  in  solution.  At 
the  end  of  this  time  a  small  sample  is  salted  out  and  spotted  on  paper,  the  clear  ring  being 
tested  with  R-salt  solution  to  detect  the  presence  of  any  diazo  body;  none  should  be 
present,  as  shown  by  the  absence  of  color  on  this  ring.  The  solution  should  also  be  alka- 
line to  Brilliant  Yellow  paper,  adjustments  being  made  in  cases  where  it  does  not  answer 
these  requirements.  After  the  coupling  is  complete  the  solution  is  heated  to  45°  and 


33  Ref.  14a,  p.  2270;  m.  p.,  174°. 


18 

enough  salt  is  added  in  small  amounts  to  obtain  a  clear,  or  slightly  colored,  ring  when 
spotted  on  paper.     The  dye  is  filtered  out  from  the  warm  solution  and  dried  at  80  °. 

These  dyes  belong  to  the  class  of  acid  colors,  dyeing  animal  fiber  from 
a  weak  acid  bath,  the  application  being  made  in  the  following  way.  As  the 
strength  of  the  several  dyes  varies  considerably  due  to  the  amount  of  salt 
present,  in  order  to  obtain  dyeings  of  approximately  the  same  strength 
for  comparison,  it  is  necessary  to  make  standard  solutions  of  500  cc.  of 
0.1%,  of  each.  These  are  spotted  on  paper  and  the  weak  and  strong  ones 
noted,  corrections  being  made  in  the  volume  of  solution  used  for  dyeing. 
For  a  2%  dyeing  on  a  10  g.  woolen  skein,  200  cc.  of  this  solution  is  used, 
and  more  or  less  is  added  according  to  the  strength.  The  measured 
volume  is  diluted  to  700  cc.,  4%  sulfuric  acid  and  15%  Glauber's  salt, 
based  on  the  weight  of  material  dyed,  being  added.  The  wool  which  has 
been  thoroughly  wet  in  warm  water,  is  immersed  and  the  whole  is  heated 
slowly  to  boiling,  while  the  skeins  are  turned  frequently  to  insure  even 
dyeing.  After  30  minutes'  boiling  the  bath  is  exhausted,  and  the  skeins 
are  removed,  washed  and  dried. 

Both  in  the  preparation  of  the  dyes  and  the  application,  approximately 
standard  solutions  of  the  various  acids,  bases  and  salts  were  used,  so  that 
the  desired  quantities  could  be  easily  measured. 

In  this  same  manner,  dyes  were  made  from  thio-anisidine  and  thio- 
ansidine  sulfone,  the  following  intermediates  being  used  in  addition  to 
R-salt:  salicylic  acid,  Schaeffer's  salt,  Neville  and  Winther's  acid,  L- 
acid,  (1-OH,  5-SOaH)  and  chromotrope  acid.  For  comparison,  the 
corresponding  dyes  were  prepared  from  ^-toluidine  and  ^-anisidine. 

2.  From  Diamines.     See  Tables  X  and  XII 

One-hundredth  g.-mole  of  the  base  is  dissolved  in  100  cc.  of  hot  water  containing 
0.04  g.-mole  of  hydrochloric  acid,  cooled  to  5°  and  diazotized  with  0.02  g.-mole  of  sodium 
nitrite,  while  an  excess  of  nitrite  is  maintained  for  one-half  hour  as  shown  by  the  starch- 
iodide  test;  0.022  mole  of  salicylic  acid  is  dissolved  in  an  equivalent  quantity  of  sodium 
hydroxide,  so  that  it  is  just  alkaline  to  Brilliant  Yellow  paper,  and  then  0.2  mole  of 
sodium  carbonate  is  added.  This  solution  is  cooled  to  5°  and  the  tetrazotized  base, 
which  has  previously  been  neutralized  to  a  slight  acidity  to  congo  red  paper,  is  added 
slowly  at  this  temperature.  After  three  hours  it  is  tested  for  excess  diazo  with  R-salt 
solution,  by  spotting  a  sample  on  paper  and  testing  the  clear  ring.  This  should  be  nega- 
tive, showing  that  the  first  molecule  of  salicylic  acid  has  coupled;  0.02  moles  of  sodium 
hydroxide  is  added  and  the  temperature  brought  slowly  to  35°,  stirring  overnight  at  this 
temperature.  In  the  morning  the  second  molecule  should  be  coupled,  and  the  solution 
should  be  strongly  alkaline  to  Brilliant  Yellow  paper.  To  test  for  excess  of  the  second 
diazo  group,  a  small  amount  of  color  is  diluted  and  divided  between  two  test-tubes,  and 
to  one  several  drops  of  1%  H-acid  solution  are  added.  Both  are  heated  to  boiling  and 
should  remain  the  same  color.  A  change  in  the  one  containing  H-acid  denotes  the  pres- 
ence of  free  diazo  group.  The  dyes  are  heated  to  50°  and  salted  out. 

Dyes  containing  salicylic  acid  are  commonly  known  as  acid  chrome  colors,  since  the 
color  is  fixed  on  the  wool  with  a  dichromate  mordant.  These  colors  were  dyed  as  follows. 


19 

A  standard  solution  of  dye  is  made  as  described  above,  and  the  quantity  measured 
to  give  a  2%  dyeing;  3%  acetic  acid  and  15%  Glauber's  salt  are  added,  the  skein  is  im- 
mersed and  boiled  for  l/2  hour.  An  addition  of  3%  acetic  acid  is  made  and  the  boiling 
continued  for  another  half  hour.  In  case  the  dye  is  to  be  chromed,  this  is  followed  by 
adding  10%  dichromate  and  boiling  for  another  half  hour,  after  .which  the  skeins  are 
removed,  washed  and  dried. 

Thio-aniline,  thio-aniHne  sulfone  and  the  diamine  from  mustard  gas,  NH2- 
C6H4SCH2CH2SCH2CH2SC6H4NH2,  were  tetrazotized  and  coupled  with  the 
other  intermediates  which  were  used  with  the  mono-amines  described  above. 

At  the  same  time  similar  dyes  from  benzidine  itself  were  prepared  for 
comparison.  The  couplings  were  made  in  the  same  way  as  with  salicylic 
acid  described  above,  except- that  sodium  carbonate  was  substituted  for 
the  hydroxide,  the  couplings  being  made  in  a  weaker  alkaline  solution. 
In  this  series  also  the  first  molecule  of  intermediate  was  coupled  at  a  low 
temperature  and,  after  testing  with  R-salt  for  uncombined  tetrazo  body, 
the  temperature  was  elevated  to  35  °  and  the  suspension  stirred  overnight. 

The  dyes  obtained  were  applied  to  wool  in  exactly  the  same  way  as  the 
acid  dyes  obtained  from  mono-amine  bases. 

Additional  dyes  were  made  with  these  same  bases  by  coupling  them 
with  intermediates  used  to  produce  direct  dyes,  using  naphthionic,  gamma- 
and  H-acids.  The  bases  were  tetrazotized  in  the  usual  way,  but  the 
couplings  were  made  in  the  case  of  the  first  two  intermediates  in  neutral 
solutions,  neutrality  being  maintained  during  the  formation  of  hydro- 
chloric acid  in  the  course  of  the  coupling;  with  H-acid  the  solution  was 
kept  alkaline  throughout  by  an  excess  of  carbonate. 

These  colors  are  applied  to  cotton  in  the  following  way. 

A  standard  0.1%  solution  of  the  dye  is  prepared  as  usual  and  the  required  volume 
for  the  desired  strength  is  diluted  to  250  cc.,  15%  of  sodium  chloride,  based  on  the  weight 
of  skein  used,  being  added.  The  skeins  are  introduced  into  the  boiling  solution  and  al- 
lowed to  remain  there  for  3/4  hour  and  frequently  turned. 

Colors  of  the  Dyes34 

1 .  Mono-amine  Bases  with  R-salt.    Dyes  from  Bases  of  Tables  II,  IV,  VI 

and  VIII 

The  first  study  was  of  the  bases  in  Table  II  to  determine  the  effect  of 
changing  the  radical  in  NH2C6H4SR,  R  being  methyl,  ethyl,  propyl, 
isopropyl,  butyl,  isobutyl,  iso-amyl  phenyl  and  benzyl.  All  of  these 
give  red  dyes  with  R-salt,  there  being  no  distinguishable  difference  in 
color  among  them  except  that  the  — SCH3  is  a  bordeaux  and  the  — SC6H5 
is  scarlet.  The  benzyl  group  acts  exactly  like  the  alkyls  higher  than  the 
methyl  group.  The  sulfur  atom  appears  here  as  strongly  bathochromic 
and  its  influence  is  so  decided  that  the  size  or  nature  of  the  group  beyond 

34  Thanks  to  Dr.  R.  E.  Rose,  the  color  designations  here  given  are  from  the  Tech- 
nical 1/aboratory  of  E.  I.  du  Pont  de  Nemours  and  Co.  « 


20 

it  makes  little  difference;  or,  what  is  more  probable,  the  part  of  the 
auxochrome  group  which  is  in  immediate  union  with  the  benzene 
nucleus  is  the  decisive  factor.  This  is  shown  by  a  comparison  of  the  iso- 
meric  bases  containing  the  groups  — SCH2C«H5  and  — CH2SC6H6.  The 
dye  from  the  first  is  deep  red,  while  that  from  the  second  is  tangerine, 
the  auxochrome  effect  of  the  sulfur  being  lost  by  the  interposition  of  the 
— CH2 —  group.  The  same  color  is  shown  by  the  dye  from  the  base  con- 
taining — CH2SC6HU  (iso).  The  oxidation  of  the  — S —  in  these  two  to 
— SO2 —  has  no  effect  on  the  color. 

Contrasting  the  amino  sulfones  of  Tables  IV  and  VIII  with  the  amino 
sulfides  of  Tables  II  and  VI  we  find  that  the  oxidation  of  — S—  to  — SO2— 
destroys  the  effect  of  the  — S —  completely;  in  fact  the  sulfone  group  is 
actually  hypsochromic,  the  dyes  from  NH2C6H4SO2R  being  gold  while 
the  one  from  aniline  itself  is  orange.  The  size  and  character  of  the  radical 
carried  by  the  sulfone  group  have  no  effect  on  the  color,  the  dyes  from  all 
the  bases  in  Table  IV  being  indistinguishable. 

A  curious  fact  appears  with  the  dye  from  NH2C6H4SCOC<,H5.  This 
contains  — S —  joined  to  the  nucleus  and,  according  to  what  was  said 
above,  was  expected  to  be  deep  red  like  the  dye  from  NHsjCeH^SCE^CeHs 
from  which  it  differs  only  in  the  oxidation  of  the  — CH2 — .  The  dye  in 
question  is  scarlet  but  its  tinctorial  power  is  so  diminished  that  only  a 
moderate  color  was  obtained  by  double  strength  dyeing.  Here  oxidation, 
even  of  a  group  beyond  the  sulfur,  has  lightened  the  color. 

2.  Mono-amine  Bases  with  Various  Intermediates 
As  it  appears  that  the  alkyl  present  in  the  sulfide  and  sulfones  is  of 
little  consequence,  further  comparisons  were  made  between  dyes  containing 
the  groups —CH3, —OCH3, —vSCH3  and  — SO2CH3;  that  is,  ^-toluidine, 
^-anisidine,  ^-thio-anisidine  and  its  sulfone  were  diazotized  and  coupled 
with  salicylic  acid,  Schaefifer's  salt,  Neville  and  Winther's  acid,  L-acid, 
R-salt  and  chromotrope  acid.  The  colors  of  the  dyes  obtained  are  given 
in  the  table  below. 

TABLE  XIII 
COLORS  OF  DYES  FROM  BASES  WITH  VARIOUS  INTERMEDIATES 

Auxochromes 
Acids  — CH»  — OCH,  — SCH,  — SOiCHj 

Salicylic  Yellow  Yellow  Yellow,  darker        Gold 

Salicylic,  chromed  Yellow  Yellow  Old  gold  Old  gold 

Schaeffer's  Orange  Scarlet  Red  Gold 

Neville  and  Winther's    Scarlet  Scarlet  Red  Orange 

L-acid  Red  Red  Bordeaux  Old  gold 

R-salt  Scarlet  Red  Bordeaux  Gold 

Chromotrope  Cardinal  Heliotrope      Violet  Red 

We  have  here  the  same  color  relations,  the  auxochromes  being  arranged 


21 

in  the  order:     —  SCH3>  —  OCH3>  —  CH3>  —  SO2CH3.     This  is  true 

regardless  of  the  nature  of  the  second  constituent  of  the  dye. 

3.  Diamine  Bases  with  Salicylic  Acid,  Chromed.     See  Tables  X  and  XII 

The  colors  obtained  are  as  follows:  (1)  benzidine,  gold;  (2)  thio- 
aniline,  old  gold;  (3)  and  (4)  the  rings  joined  by  —  CH2S  —  and  —  CH2- 
SCH2—  ,  old  gold;  (5)  by  —  SCH2S—  ,  old  gold  but  deeper;  (6)  and  (7)  by 
—  SCH2CH2S—  and  —  SCH2CH2SCH2CH2S—  ,  gold.  The  presence  of 
sulfur  connected  to  two  rings  in  thio-aniline  darkens  the  color  considerably 
as  compared  with  benzidine.  The  introduction  of  one  or  two  methylene 
groups  with  one  sulfur  atomjveakens  the  coloring  property,  and  the  sul- 
fone  is  still  weaker.  In  the  case  where  two  sulfur  atoms  are  separated 
by  CH2,  the  color  is  practically  the  same  as  with  thio-aniline,  the  influence 
of  the  CH2  being  overcome  by  the  relatively  large  amount  of  sulfur  ad- 
jacent. Where  the  sulfur  atoms  are  farther  apart,  being  separated  by 
ethylene,  the  color  is  much  lighter  and  more  greenish,  lacking  the  reddish 
overcast  obtained  with  thio-aniline  and  its  sulfone.  Where  the  two  rings 
are  separated  by  three  sulfur  atoms  and  two  ethylene  groups,  the  color 
is  still  darker  and  greener,  while  the  introduction  of  a  sulfone  group  in 
the  center  between  the  two  ethylenes  does  not  change  the  color  at  all, 
showing  again  that  the  sulfur  atoms  connected  directly  to  the  rings  are 
the  ones  that  exert  the  most  influence  on  the  color. 

The  sulfone  of  thio-aniline  gives  an  old  gold,  the  same  as  thio-aniline 
but  darker  apparently  reversing  the  relationship  found  above  between 
sulfides  and  sulfones.  The  dye  from  mustard  gas  sulfone  is  practically 
the  same  as  that  from  mustard  gas,  which  is  as  would  be  anticipated  since 
the  —  SO2—  in  the  group  —  SCH2CH2SO2CH2CH2S—  cannot  be  expected 
to  show  much  effect. 

For  these  diamines,  alicylic  acid  was  used  because  of  the  importance 
of  Anthracene  Yellow  C  (Cassella)35  obtained  by  coupling  this  inter- 
mediate with  thio-aniline.  The  couplings  were  made  in  the  following 
way,  as  were  also  the  acid  colors  described  subsequently. 

XIV 


COLORS  OF  DYES  FROM  CERTAIN  DIAMINES  COUPLED  WITH  VARIOUS  INTERMEDIATES 


Acids 

Benzidine 

—  s  — 

—  SOj— 

(SCH,CHz),S 

Salicylic  (chromed) 

Yellow 

Gold 

Gold 

Yellow 

Schaeffer's  salt 

Maroon 

Scarlet 

Orange 

Scarlet 

Neville  and  Winther's 

Heliotrope 

Red 

Scarlet 

Red 

L-acid 

Claret 

Claret 

Burnt  orange 

Red 

R-salt 

Purple 

Claret 

Burnt  orange 

Red 

Chromotrope 

Purple 

Heliotrope 

Claret 

Heliotrope 

Gamma-acid 

Violet 

Claret 

Claret 

Red 

Chicago  acid 

Purple 

Lilac 

Maroon 

Violet 

H-acid 

Blue 

Purple 

Maroon 

Lilac 

35  Schultz,  "Farbstofftabellen,"  1914,  p.  294. 


22 

4.  Diamine  Bases  with  Various  Intermediates 

The  dyes  from  thio-aniline,  thio-aniline  sulfone  and  the  diamine  from 
mustard  gas  when  coupled  with  various  intermediates  are  contrasted 
with  those  from  benzidine.  The  colors  are  given  in  Table  XIV.  This 
series  of  colors  indicates  that  where  the  diphenyl  rings  are  separated 
by  sulfur,  sulfone  and  other  groups,  they  no  longer  possess  the  properties 
of  benzidine,  which  gives  colors  varying  from  deep  reds  to  blues  and  violets. 
The  thio-aniline  and  its  sulfone  give  much  lighter  colors,  differing  slightly 
but  practically  in  the  same  range  of  the  spectrum  as  those  obtained  from 
the  mono-amines  coupled  with  the  same  acids,  though  the  molecular  weight 
is  greater  than  that  of  the  benzidine  dyes  and  approximately  double  that 
of  the  mono-amine  series.  The  dyes  containing  three  sulfur  atoms,  with 
the  mustard  gas  residue  between,  are  also  slightly  lighter  than  those  from 
thio-aniline. 

In  this  series  the  sulfur  divides  the  molecules,  so  that  the  colors  obtained 
appear  as  if  each  half  were  acting  as  a  unit,  while  with  benzidine  the  effect 
of  each  group  is  felt  in  the  opposite  ring. 

The  three  diamine  bases  having  — SCH2S— ,  — SCH2CH2S—  and 
— SCH2CH2CH2S —  between  the  rings  were  coupled  with  gamma-acid. 
The  dyes  from  the  first  two  were  red  and  practically  identical,  but  the  last 
gave  a  maroon. 

The  conclusion  drawn  above,  that  these  diamine  bases  do  not  possess 
the  properties  of  benzidine,  is  borne  out  by  the  fact  that  they  do  not 
form  direct  cotton  dyes.  Benzidine,  coupled  with  gamma-acid  or  H-acid, 
forms  colors  which  dye  cotton  direct  from  a  salt  bath.  Those  obtained 
from  the  three  sulfide  bases  used  in  the  previous  series,  when  coupled  with 
intermediates  suitable  for  producing  direct  colors,  are  found  to  be  lacking  in 
this  property.  The  benzidine  dyes  exhaust  the  bath  completely,  while  the 
others  do  so  only  in  part;  some  color,  however,  remains  in  the  fibre.  The 

TABLE  XV 

COLORS  OF  DYES  FROM  DIAMINE  BASES  COUPLED  WITH  SEVERAL  INTERMEDIATES  AND 

DYED  OVER  COTTON 

Intermediates  Benzidine  — S —                          — SOr—          =  (SCHjCHi)jS 

Naphthionic  acid          Red  Burnt  orange  Burnt  orange       Gold 

Gamma-acid                  Violet  Claret  Claret                    Maroon 

H-acid                           Blue  Blue  Lilac                      Violet 

dyes  from  the  trisulfide  bases  from  mustard  gas  show  some  tendency  to- 
wards being  direct,  as  the  colors  do  not  wash  out  in  cold  water.  The  mono- 
sulfides  are  poorer,  and  in  the  case  of  the  sulf ones  practically  all  of  the 
color  washes  out  in  cold  water.  On  the  other  hand,  all  of  them  are  removed 
in  boiling  water. 

Table  XV  gives  the  colors  of  these  dyes  on  cotton.     Here  also  the  color 


23 

effect  produced  by  the  sulfide  and  sulfone  groups  is  the  same  as  with 
the  acid  dyes  previously  described  . 

Summary 

A  series  of  bases,  £-NH2C6H4SR,  has  been  made  and  these  have  been 
diazotized  and  coupled  with  R-salt  to  find  the  effect  of  changes  in  the  rad- 
ical R  on  the  color.  Dyes  have  been  made  from  £-toluidine,  £-anisidine, 
^-thioanisidine  and  its  sulfone  by  diazotizing  and  coupling  with  a  number 
of  intermediates.  It  has  been  found  that  — SCH3  >  — OCHa  >  — CH3  > 
— SC^CHs  act  as  auxochromes. 

Diamine  bases  of  the  type^,//-NH2C6H4-X-C6H4NH2  have  been  made 
in  which  X  is  — S— ,  —SO2— ,  — SCH2— ,  — SCH2&— ,  — SCH2CH2S— , 
— - SCH2CH2SCH2CH2S— ,  etc.,  and  these  were  tetrazotized  and  coupled 
with  various  intermediates  to  find  the  effect  of  the  group  between  the  two 
rings  on  the  color  of  the  dyes.  These  bases  do  not  resemble  benzidine  in 
giving  fast  cotton  dyes. 


BIOGRAPHY 

William  Robert  Waldron  was  born  at  New  Germantown,  New  Jersey, 
May  27,  1894.  He  received  his  early  education  at  Barnet  Hall  Academy 
in  that  place,  and  in  1913  was  graduated  from  Somerville  High  School. 
He  entered  Cornell  University  the  following  fall  and  received  the  degree 
of  Bachelor  of  Arts  in  February  1917,  spending  the  remainder  of  the  year 
there  in  the  Graduate  School.  The  first  six  months  after  leaving  were 
spent  in  the  employ  of  the  Benzol  Products  Co.  of  Marcus  Hook,  Pa. 
At  the  beginning  of  1918  he  was  engaged  by  K.  I.  du  Pont  de  Nemours  & 
Company  of  Wilmington,  Del.  where  he  remained  until  he  entered  the 
Graduate  Department  of  Chemistry  of  the  Johns  Hopkins  University  in 
1920. 


AN  INITIAL  FINE  OP  25  CENTS 

OVERDUE  $l'°°    °N    ™E    SEVE"T« 


Makers 
,!     Syracuse,  N.  Y. 


PAT,  JAM  21,  1908 


; 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


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•:-*/?-  •••-;. 


